Abstract: Memory cell transistors with back-channel isolation are produced without using an SOI substrate. With the word line stack acting as a mask, the semiconductor material is etched on both sides of the world line, first anisotropically and then isotropically to widen the etch hole and form an undercut beneath the gate electrode and at a distance from the ONO storage layer forming the gate dielectric. The undercut is filled, whereby a buried oxide layer of at least 20 nm maximum thickness is formed underneath the channel region. The latter is p-doped at a density of at least 10 17 cm −3 .

Abstract: In recent years, laser beam welding using two laser beams, or dual-beam laser welding, has become an emerging welding technique. Previous studies demonstrated use of dual-beam laser processing can delay humping onset to higher speeds and slow down cooling rates. In this study, a detailed investigation was performed to quantify the benefits of dual-beam laser processing and to understand the mechanism for improving weld quality. A 6-kW CO 2 laser beam was split into two equal-power beams and the dual beams were located in tandem (one beam follows another) during welding. Experimental results indicated the dual-beam laser could significantly improve weld quality. For steel, surface quality was improved with fewer surface defects such as undercut, surface roughness, spatter, and underfill. Weld hardness and centerline cracking susceptibility were also reduced. In aluminum, quality improvements were in the form of smooth weld surfaces and fewer weld defects such as porosity, surface holes, and undercut. A high-speed camera investigation of welding vapor plumes above a workpiece showed plume height and size changed damatically in conventional single-beam laser welding and the average fluctuation frequency was 1.2 kHz for steel. As the plume fluctuation was associated with keyhole instability, unstable vapor plume indicated the process was unstable and would result in poor welds. The vapor plumes in dual-beam laser welding were found to fluctuate at a certain frequency range, but the plume size changed only slightly during welding. The stabilized process contributed to improved weld quality in dual-beam laser welding.

Abstract: We investigated undercut phenomena on a (1 0 0) silicon wafer to explain why a (3 1 1) plane appears under the convex corner of a masking area, and why the plane is stable during the etching process. We analyzed the etching rate as a function of crystallographic orientations and found that the (3 1 1) plane has unique etching characteristics. The (3 1 1) plane is located at the saddle point in the etching-rate diagram. Based on this, we made an undercut model, which provides clear answers to the above questions. We demonstrated that our model can also explain the etched-profile change in terms of the change in the mask shape when a windmill-shaped etching mask is used.

Abstract: Disclosed herein is a method of etching deep trenches in a substrate which utilizes the overlying mask structure to achieve a trench having a positive tapered sidewall angle of less than about 88° The method employs the successive etching of a lateral undercut in the substrate beneath a masking material, while at the same time etching vertically downward beneath the mask The coordinated widening of the lateral undercut at the top of the trench, while vertically extending the depth of the trench, is designed to provide the desired trench sidewall taper angle

Abstract: Photoelectrochemical (PEC) etching is restricted to a group III nitride semiconductor-barrier interface to laterally etch or undercut the target group III nitride. The barrier interface is provided by the transparent sapphire substrate on which the target group III nitride is epitaxially grown or by a layer of material in intimate contact with the target group III nitride material and having a bandgap sufficiently high to make it resistant to PEC etching. Due to the first orientation in which this effect was first observed, it has been named backside-Illuminated photoelectrochemical (BIPEC) etching. It refers to a preferential etching at the semiconductor-barrier layer interface. The assembly can be exposed to light from any direction to effectuate bandgap-selective PEC etching. An opaque mask can be applied to limit the lateral extent of the photoelectrochemical etching.

Abstract: H2O vapor is used as a processing gas for stripping photoresist material from a substrate having a patterned photoresist layer previously used as an ion implantation mask, wherein the patterned photoresist layer is defined by a photoresist crust covering a bulk photoresist portion. Broadly speaking, the H2O vapor is demonstrated to more efficiently strip the photoresist material having a cross-linked photoresist crust without causing the photoresist crust to pop and without causing the bulk photoresist to be undercut. Thus, H2O vapor provides a safe, efficient, and economical processing gas for stripping photoresist material having a photoresist crust resulting from an ion implantation process.

Abstract: A compressor blade includes an airfoil portion having a leading edge, a radially inner attachment portion, and a platform between the airfoil portion and the attachment portion, wherein material is removed from the attachment portion to form an undercut at a front face thereof to thereby provide an overhang radially inward of the platform and leading edge of the airfoil portion.

Abstract: PROBLEM TO BE SOLVED: To effectively improve the stickiness on the other metal in a simple process and also, to keep a desired positioning precision of a clamp. SOLUTION: A cylinder liner 10 arranges the surface 16 having cast-in members on the outer peripheral surface and on the surface 16 having the cast-in members, a plurality of projections 20 having almost conical-state undercut part 18 spread toward the outer part, are arranged. At the tip part of each projection 20, a flattened part 21 corresponding to the tip part of the undercut part 18, is arranged. COPYRIGHT: (C)2004,JPO

Abstract: PROBLEM TO BE SOLVED: To improve the stickiness on the other metal which can arrange a plurality of projections having a desired shape of undercut part on the surface of a cast-in member in a simple process. SOLUTION: Facing agent 30 is coated on the inner peripheral surface 34 of a mold 30. The facing agent 36 is formed as a plurality of spherical parts 36b, and molten cast iron 40 is poured into this mold 30 while rotating the mold 30 under state of replacing into inert gas in the mold 30. The molten iron 40 is filled up to the undercut parts 36c while covering the spherical parts 36b. COPYRIGHT: (C)2004,JPO

Abstract: A turbofan and a mold used to manufacture the same, which enables the turbofan to be integrally molded by a single molding process. The turbofan has a rotating plate coupled to a shaft of a driving motor at its center, a plurality of blades radially disposed at and integrally formed with a periphery of the rotating plate, and a ring-shaped shroud integrally formed with front ends of the blades to face the rotating plate. The mold has a first mold part having a rear molding member to shape a rear portion of the rotating plate; a second mold part to be combined with the first mold part and having a front molding member to shape a front portion of the turbofan at an area corresponding to the rear molding member; a plurality of slide cores adapted to be radially moved to shape an inner surface of the shroud, outer portions of a front surface of the rotating plate, and outer surfaces of the blades; and a plurality of auxiliary cores extending to the inner surface of the shroud from the rear molding member of the first mold part to shape undercut portions of inner surfaces of the blades.

Abstract: A new collector undercut process using SiN protection sidewall has been developed for high speed InP/InGaAs single heterojunction bipolar transistors (HBTs). The HBTs fabricated using the technique have a larger base contact area, resulting in a smaller DC current gain and smaller base contact resistance than HBTs fabricated using a conventional undercut process while maintaining low C/sub bc/. Due to the reduced base contact resistance, the maximum oscillation frequency (f/sub max/) has been enhanced from 162 GHz to 208 GHz. This result clearly shows the effectiveness of this technique for high-speed HBT process, especially for the HBTs with a thick collector layer, and narrow base metal width.

Abstract: PROBLEM TO BE SOLVED: To determine visually whether brazing material 16 is defective in a circuit device 10 mounted through the intermediary of the brazing material 16 SOLUTION: A conductive pattern 11 is exposed at a recess 15 cut in the side of an insulating resin 16, the brazing material 16 is attached to the exposed conductive pattern 11, the circuit device 10 is mounted on a mounting board, and it is visually determined whether the brazing material 16 is defective The recess 15 is formed by cutting out an undercut from the peripheral conductive pattern 11, so that the conductive pattern 11 superior in wettability with the brazing material 16 is exposed at the side and top surface of the recess 15 Therefore, the brazing material 16 is attached to the side and top surface of the recess 15, so that the brazing material 16 is extended outside of the mounting region of the circuit device 10 Therefore, it is surely and visually determined whether the brazing material 16 is defective COPYRIGHT: (C)2004,JPO&NCIPI

Abstract: A bilayer mask employed for lift off has a top strip which bridges between first and second bilayer portions and is completely undercut so that when one or more materials is sputter deposited the materials do not form fences abutting recessed edges of a bottom layer in undercuts below a top layer. Sacrificial protective layers are formed on a sensor and lead layers for protecting these components while overlapping portions of these materials on the top of the sensor formed during deposition can be removed by ion beam sputtering, after which the sacrificial protective layers can be removed by ion milling or reactive ion etching.

Abstract: A method of producing surface acoustic wave devices comprising the steps of forming a first film on a piezoelectric board, forming a second film on the first film, forming a resist pattern of predetermined shape on the second film, isotropically or anisotropically etching the second and first films with the resist pattern used as a mask, isotropically etching the first film alone into an undercut form, removing the resist patter, forming an electrode material layer on the entire surface, and lifting off the electrode material layer present on the second film by etching the second film for removal, thereby forming electrodes.

Abstract: Increased demand for fiber-optic technology has created significant growth in the sales of interconnection devices such as fiber-optic connectors, cable assemblies, and adapters. To ensure good connector performance during actual use, several process parameters related to geometric and optical characteristics of the connector must be thoroughly understood during the manufacturing stage. The experimental design has been used here to see the influence of applied pressure and time on the fiber end geometry as well as optical performance. The mathematical model is also applied to explain the phenomena of the present fiber undercut-reflectance relation. By a proper choice of polishing film grit size and processing conditions, it is possible to obtain fiber connectors with less fiber undercut and better return loss. Influences of film grit size and rubber-pad thickness on the reflectance and the fiber undercut are also presented.

Abstract: A semiconductor device having a chamfered silicide layer and a manufacturing method of the same. The semiconductor device includes: a first insulation layer overlying a semiconductor substrate; gate structures including first conductive layer patterns formed on the first insulation layer, and second conductive layer patterns which are formed on the first conductive layer patterns, wherein the lower sides of the second conductive layer patterns are substantially perpendicular to the major surface of the semiconductor substrate and the upper sides of the second conductive layer patterns are chamfered; and a second insulation layer formed with a first width W on the second conductive layer patterns, wherein the sidewalls of the second insulation layer overhang the upper edges of the second conductive layer patterns. In the semiconductor device manufacture, in forming undercut regions which define the chamfered upper edges of the metal silicide layer patterns, isotropic dry etching is carried out, wherein the isotropic dry etching can be performed simultaneously with ashing of photoresist patterns, or immediately after the ashing process in the same chamber. In either case, after the ashing of the photoresist patterns, an isotropic wet etching can be carried out immediately after performing an existing stripping process, so as to form the undercut regions.

Abstract: The procedure for joining two components (1, 2), e.g. for attaching a component to a vehicle trim strip, uses a plastic or other soft self-hardening material (3) inserted into adjoining cavities in the two components, one of which is undercut to ensure a reliable fixing. The plastic or soft material is poured or molded in the cavities and allowed to set to form a reliable fixing. The undercut cavity can be made in a variety of shapes, including dovetail or hooked section, and it can be used to hold one end of a fastener that receives the second component. The plastic material, preferably a plastomer or elastomer, can be applied manually or with a pneumatic tool and can, where necessary, be heated to harden it.

Abstract: A method of making or reconstituting a steel tooling used in the processing of high temperature molten material includes machining an undercut surface in the tooling which provides an inset edge trapping receiving surface with an end marginal wall. The undercut is prepared for the reception of a barrier layer which fills the undercut and merges with the tooling surface bordering the undercut. Then a chemical barrier providing wear resisting coating surface which is thermally expansively and contractibly compatible with the tooling surface to avoid fracturing stresses due to differential rates of thermal expansion and contraction at elevated temperatures is fused to the receiving surface.

Abstract: A novel method by using adjusted ultrasonic agitation to improve the developing depth, developing time, surface roughness, and undercut problem of thick JSR-430N negative UV photoresist is proposed. This method has been successfully employed to fabricate ultra-thick microstructures of thickness more than 1.4 mm and aspect ratio at least of 5 by JSR THB-430N negative UV photoresist. With the improved ultrasonic developing procedure, the resist can potentially be a replacement of SU-8 resist for the application of high aspect ratio plating mold, due to its good stripping property [1]. The power and angle of ultrasonic agitation have also been studied and characterized. The development of thick JSR-430N resist under different ultrasonic agitation angles has been verified to have different effects on developing time, resist sidewall profile, and surface roughness.

Abstract: PROBLEM TO BE SOLVED: To integrally mold a small-size molded part having an undercut in the inside. SOLUTION: A cavity 21 is formed between a cavity block 11 incorporated into a fixed side retainer plate 4 and a cavity block 31 incorporated into a movable side retainer plate 24. A slide core 12 is incorporated slidably in the direction of the parting line 1 into the fixed side retainer plate 4. A recessed part 12a having a slope opened on the side of a fixed side bottom plate 7 is formed in the slide core 12, and the tip is hung down to be inserted into the cavity 21 and has an undercut 12b in the inserted part. The slope 16a of the first locking block 16 is engaged with the recessed part 12a, and the second locking block 17 supports the undercut 12b. A compression coil spring 15 is engaged with a shoulder bolt 13 between the rear end of the slide core 12 and a stopper 14, and the tip of the slide core 12 is biased toward the center of the cavity 21.

Abstract: of EP1249286The deforming process involves feeding a fluid (16) into the shaping cavity (15) where it builds up an internal pressure acting in all directions. The material is thus diverted into the pierced joint point of the sheets (1, 2), increasing the deforming effect on the undercut (9) with reduced surface pressure.

Abstract: This thesis deals with different methods to improve the adhesion between sputtered aluminium and positive photoresist Factors controlling the adhesion and different ways to measure the adhesion have been investigated Different surface treatments prior to resist disposition have been investigated as well The investigated surface treatments and adhesion measurements are compatible with the available equipment and the existing process cycle at Strand Interconnect AB All tests were made in class 1000 clean room All tests in this thesis were performed with MICROPOSIT S1818 SP16, which is a commercial and commonly used positive resist manufactured by Shipley To provide sufficient adhesion on the aluminium surface some kind of surface treatment must be used Today a wet chemical treatment is used at Strand Interconnect In this report methods to modify the surface properties and to measure the adhesion have been investigated The three methods to modify the aluminium surface were oxygen plasma, wet chemicals and primers and were used in this thesis The RF power and time duration of the oxygen plasma were varied, while the temperature, gas flow and pressure were fixed The adhesion was determined indirectly from measuring contact angles of 50 µl DI water droplets on sputtered aluminium in the wettability test as well as directly from the undercut caused by the etch fluid at the interface between the photoresist and the aluminium surface An oxygen plasma with 200 W power for 30 s resulted in the lowest measured contact angle, which means that the resist adheres well on the surface The angle was 299 degrees compared to 634 degrees for the wet chemical treatment used today The same treatment also resulted in the lowest undercut, which correlates well with the result from the contact angle measurements The measured undercut for a 25µm wide conductor was 141 µm, corresponding to an undercutting constant (ku) of 1410 The wet chemical surface treatment used today resulted in an undercut of 160 µm, equivalent to a ku of 1233 Similar results were obtained for a 15 µm wide conductor

Abstract: An undercut (9c) on the outer surface of the molding (9) is formed by the internal faces of slides (1) in the tool. During demolding the angled slides move both axially and sideways relative to the tool axis to release themselves from the molded undercut.

Abstract: PROBLEM TO BE SOLVED: To simply mold a strong undercut product to mold a hollow product by a die sliding method. SOLUTION: A method for injection molding comprises the steps of molding product halves 5 and 6 on mating surfaces of first to third molds 1, 2 and 3 by matching the molds in series, then retarding the central second mold 2, thereafter butting the first and third molds 1 and 3, secondarily matching the molds 1 and 3, and secondarily injecting to adhere the butted halves 5 and 6 to manufacture the product 7.

Abstract: PROBLEM TO BE SOLVED: To readily take out a molded foam from a mold. SOLUTION: A cavity part 14 formed between an upper mold 10 and a lower mold 12 is tightly closed by seal members 20a and 20b, and high pressure is applied by delivering air through a fluid injection passage 22 (a process (b)). Thereby, a urethane foaming object 28 is compressed within the cavity 14 and removed from the mold. Further, upper mold coupling parts 16a and 16b and lower mold coupling parts 18a and 18b are provided in order to maintain a closed state even when the mold is slightly opened. Accordingly, in the case where undercut parts 24a-24e are present, the upper mold 10 opens with the urethane foaming element 28 in a compressed state enabling the object 28 to be removed from the undercut parts 24a-24b (processes (c) and (d)). COPYRIGHT: (C)2004,JPO

Abstract: PROBLEM TO BE SOLVED: To provide a molding method which can easily mold a centrifugal fan having twisted blades in a shape having an undercut and a molding mold for the method. SOLUTION: In the molding mold for the centrifugal fan, the centrifugal fan having a plurality of the twisted blades integrally is held in its central axis direction between the peripheral parts of one surface of a cone and molded, and after the molding, the molding mold for the centrifugal fan is extracted to one surface side and the other surface side of the cone in relation to the centrifugal fan. The molding mold on one surface side of the cone is divided into the first mold for molding the non-undercut part of each twisted blade and the second mold for molding the undercut part of each twisted blade by a split surface which makes a surface parallel to the central axis approximately along the form of each twisted blade. At least the second mold is constituted to be able to rotate around the central axis, and the second mold is made to be extracted without interfering with the molded twisted blades.

Abstract: The disclosure relates to measuring an undercut of a feature on a specimen using a scanning electron microscope (SEM). In accordance with one embodiment, a method for measuring the undercut includes illuminating the feature with a primary electron beam at an incident angle, changing the incident angle of the primary electron beam over a set of angles, measuring an intensity of scattered electrons from the feature for each incident angle in the set of angles, and determining a discontinuity in the intensities as a function of the incident angle.

Abstract: The first and second parts are molded in separate tools. Another part forming a connecting member is injected onto both parts to form a single component. The first part forms a rigid support(3) and the second part forms a soft seal(5) with an arc-shaped sealing lip. Following injection of the first two parts the two tools are opened and each part remains in a tool half. The two tool halves are then moved together so that the two moldings are in their final molding positions. A further tool part(11.3) is inserted between the tool halves to form a molding cavity(10.3) for the connecting member. The first and second tools are fed with plastic melt from different machines and the third tool is fed from one of these machines. First and second parts are injected simultaneously and have no undercut areas. When completed the final product includes an undercut between the first and second parts. An Independent claim is included for a component comprising first and second parts joined together by a connecting part injected onto them.

Abstract: The sheet (1) consisting of a textile material, is provided along its edge with an insert (2), and is anchored in an undercut profile rail (3) by the insert whose non deformed diameter is larger than the width of the entry slit of the rail. The sheet (1) consisting of a textile material, is provided along its edge with an insert (2), and is anchored in an undercut profile rail (3) by the insert whose non deformed diameter is larger than the width of the entry slit of the rail. At the same time, the diameter of the elastically recoverable insert can be reduced by tensile or compressive forces so that the edge of the material sheet can be passed through the entry slit of the rail. An Independent claim is also included for a combination comprising a profile rail carrying a material sheet with a rod inserted along its edge.